Well, this is a tricky one...the only things I can suggest are to:
Reboot the router
Disable & then re-enable the card from Device Manager (I'm assuming you're on Windows)
If you can, try to connect the computer to the router with a Cat 5/5e/6 Cable and see if it works
I have tried all of these except hooking my computer direct to the router with a cable, still hasn't helped...I guess I was just wondering if others were having any issues with using a different brand router and wireless card? I had my laptop home last night and it work fine right next to my desktop, which was having issues with connectivity.